When evaluating OTC dry-eye drops (primarily artificial tears), there are two primary features to be aware of: The viscosity of the product, and the preservative used.

The preservative helps to extend the life of the product and, more importantly, reduce the likelihood of contamination by bacteria. However, some preservatives also can damage the eye and cause stinging and burning when used over lengthy time-periods. Preservative-free artificial tears avoid these problems, but must be supplied in unit-dose containers to avoid contamination, which significantly increases cost. Newer preservatives such as Polyquad, which are also found in contact lens solutions, are generally less harmful to the eye.

Generally, the more viscous the drop, the longer it will remain on the eye, and therefore the longer the effect of the artificial tear. The disadvantage of higher viscosity, as users of these products will recognize, is blurred vision. Individuals with mild dry-eye will often be happy with a low-viscosity drop such as Theratears or Refresh Plus . For moderate dry-eye, try Theratears Liquid Gel, or Refresh Liquigel. As always, if your dry-eye does not respond to these simple remedies, or if your symptoms appear to be getting worse with time, you should consult your eye-doctor.